Method for the identification of a service

ABSTRACT

The invention relates to a method for the identification of a service, requested by a call to a mobile communication unit from and/or via a fixed network and via a mobile communication network. All available part information relating to the carrier capabilities specific to the service are collected, collated and evaluated for the identification of the service and transmitted to the mobile communication unit.

CLAIM FOR PRIORITY

This application is a national stage of PCT/DE01/04389, published in theGerman language on Jun. 12, 2003, which was filed on Nov. 19, 2001.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for identification of aservice, and in particular, requested by a call to a mobilecommunications unit from and/or via a landline network and via a mobilecommunications network.

BACKGROUND OF THE INVENTION

In digital mobile communications networks and in PLMNs (Public LandMobile Network), for example in a GSM or an UMTS network, a call to acommunications unit, by means of which a specific service is requested,is generally signaled in advance in a so-called call set-up phase to thecommunications unit. This means that specific information is transmittedfor the call and for the service. Requested services may in this casebe, for example, a speech service, a data service or a fax service.Prior signaling is used to provide a network and/or a terminal, such asa mobile communications unit, with the capability to check whether therequested service can be supported or whether a user is in factauthorized to use a specific service. Furthermore, the appropriateprecautions for setting up the call can be taken on the basis of callsignaling such as this. The information which is specific for a call orfor a service which is being requested by a call is in general signaledin a signaling message, a so-called call set-up message.

In this case, it is in turn associated with well-defined informationelements, depending on the nature of the information. One of theinformation elements contains all of the call-specific and/orservice-specific bearer capabilities, and this is referred to as the BC(Bearer Capability). A second information element is referred to as LLC(Low Layer Compatibility), and a third is referred to as HLC (High LayerCompatibility). These information elements must be provided by thecommunications unit from which the call originates. While LLC and HLCinformation elements are transparent while they are being transportedthrough the networks to be passed through, the BC information elementmay vary depending on the requirements of the individual networks. Forexample, different BC information elements are defined for an ISDN and aPLMN. These BC information elements are mapped onto one another atinterfaces between the various networks.

One problem in this case is that the supplied information elements to bemapped are generally not complete. Either the communications unitoriginating the call does not provide all of the information expected bythe communications unit receiving the call, or a network to be passedthrough is not able to transport the information. The latter is thecase, for example, when the networks to be passed through include ananalog network, such as a PSTN (Public Switched Telephone Network) ornational versions of ISDN signaling mechanisms. In the situation wherethe communications unit receiving the call is a mobile communicationsunit, it is problematic for the mobile communications network todetermine which service is being requested by the call.

GSM/UMTS Standards in this case specify two different mechanisms, withone of the mechanisms being referred to as the single-numbering scheme,and the second as the multi-numbering scheme.

In the case of the single-numbering scheme, a user or a mobilecommunications unit receives only one number, which is valid for all theservices which the user is authorized to use. In this case, it isassumed that a requested service from a landline network can beidentified, for example, by means of the information which is suppliedby the information elements BC, LLC, HLC. The information element BC(referred to for short in the following text just as BC) which, by wayof example, is received from ISDN, is mapped onto a PLMN BC in the PLMN,that is to say, to be more precise, in a Mobile Switching Center (MSC),Visited Mobile Switching Center (VMSC), which is responsible for themobile communications unit at the time at which the call was set up.This PLMN BC is sent to the mobile communications unit when it iscomplete. According to the GSM/UMTS Standards, it is not permissible tosend an incomplete BC to the mobile communications unit. If the PLMN isnot able to create a complete BC, then no BC is sent to the mobilecommunications unit. In this case, the mobile communications unit mustselect the service without having any information relating to theservice. If the service which is selected by the mobile communicationsunit does not correspond to the service coming from the landlinenetwork, then the call requesting the service is rejected. If, by way ofexample, the mobile communications unit selects a speech service but adata service is coming from the landline network by means of a modem,then no call is set up. The single-numbering scheme can thus be usedwell when the landline network supplies sufficient information to makeit possible to create a complete BC.

In the case of the multi-numbering scheme, a user or a mobilecommunications unit receives different numbers, specifically for eachservice which he is authorized to use, one and only one. In consequence,the communications unit from which a call to request a serviceoriginates dials the specific service just by entering an appropriatenumber. A corresponding complete PLMN BC which is associated with thatnumber, is stored in an HLR (Home Location Register) in the PLMN. Inthis case, each number is associated with one, and only one PLMN BC. Thecomplete PLMN BC which identifies the requested service is sent to amobile communications unit receiving the call. In this case, it may bepassed from the HLR via a VLR (Visitor Location Register) and theVisited Mobile Switching Center (VMSC) to the mobile communicationsunit. The multi-numbering scheme can be used when the landline networkcannot supply sufficient information.

The advantage of the single-numbering scheme is the fact that numbersare saved. The disadvantage is that, in the situation where it is notpossible to create a complete BC, the mobile communications unit has toselect a service without any information.

The multi-numbering scheme has the advantage that the mobilecommunications unit receives a complete service-specific BC. However, inthis case, a very large range of numbers must be made available for oneand the same user, specifically one number for each service which theuser may use. This disadvantage becomes more significant as the range ofnumbers which can be allocated is restricted, and the number of users inthe present-day networks is increasing continuously.

SUMMARY OF THE INVENTION

In one embodiment of the invention, there is a method while allocating aminimum number of numbers for one and the same user of a mobilecommunications unit, to allow a service to be identified precisely withas high a probability as possible, that is to provide information whichis as complete as possible relating to bearer capabilities which arespecific for a service or for a corresponding call.

In another embodiment of the invention, there is a method foridentification of a service, requested by a call to a mobilecommunications unit from and/or via a landline network and via a mobilecommunications network in which all of the available informationelements relating to the bearer capabilities which are specific for thatservice are collected, are collated, are assessed for identification ofthe service, and are signaled to the mobile communications unit. Themobile communications network is in this case generally a so-called PLMN(Public Land Mobile Network), as already mentioned. The landline networkmay, for example, be an ISDN (Integrated Services Digital Network) or aPSTN (Public Switched Telephone Network).

In one preferred embodiment of the method according to the invention, anadditional information element is provided in a signaling message (callset-up message) to the mobile communications unit with informationelements (LLC, HLC, BC) which are specific for that call, in which allthe available, gathered information elements relating to the bearercapabilities which are specific for that call are collated. Thisadditional information element will be referred to as BACKUP in thefollowing text. While, on the basis of the GSM/UMTS Standards, it is notpermissible to send an incomplete BC to a mobile communications unit,the BACKUP which is provided according to the invention may also haveincomplete information relating to the bearer capabilities which arespecific for a call. In comparison to no BC, the BACKUP which is sent inthe signaling message, the so-called call set-up message as alreadymentioned in the introduction, to the mobile communications unit, meansthat there is a very much higher probability that the network and/or themobile communications unit can identify the call and can check in acorresponding manner whether it can support the service corresponding tothe call and/or whether the user is authorized to use that service. Ifrequired, appropriate precautions may be taken in order to receive thecall. Furthermore, the user has only a single number, which isassociated with him for all the services, and this has the advantagethat the operator of the mobile communications network, that is to sayin general of the PLMN, can save numbers.

In a further preferred embodiment of the method according to theinvention, the additional information element (BACKUP) is created in aVisited Mobile Switching Center (VMSC) in the mobile communicationsnetwork. As already mentioned, the user or the mobile communicationsunit is allocated a number, which is stored in a corresponding HLR (HomeLocation Register). If a call for this number now arrives in the PLMN ata Gateway Mobile Switching Center (GMSC) then the GMSC turns to aresponsible HLR in order to determine the location of the mobilecommunications unit of the user being called. To do this, the HLR inturn uses a request message (provide roaming number) to request aso-called roaming number from a corresponding VLR (Visitor LocationRegister) which is responsible for the present location of the user.This roaming number allows the call to be passed on to the VMSC which isresponsible for the mobile communications unit, so that the VMSCreceives the originally signaled information. At the same time, the HLRhas used the request message to the VLR to also supply all of theavailable information relating to the bearer capabilities which arespecific to that call. Depending on the implementation, this is eitherthe originally received information (ISDN BC) or the PLMN BC formed inthe HLR. In the latter case, the PLMN BC is not supplied unless it iscomplete. A VMSC which is responsible for the mobile communications unitcalls up this information from the VLR. If the VMSC is not able to forma complete PLMN BC on the basis of the received information, it thuscreates the additional information element BACKUP, which it then sendsto the mobile communications unit in a signaling message.

In another preferred embodiment, the additional information element(BACKUP) may in fact also be created in a responsible HLR. It is thensupplied to the VLR in the request message as mentioned above, fromwhere it is then available to the VMSC.

All the information which is included in the additional informationelement is preferably obtained from the landline network, that is to sayfor example from an ISDN or PSTN and/or from the mobile communicationsnetwork, that is to say in general a PLMN. An ISDN provides at least oneITC (Information Transfer Capability) information item. This parameterindicates whether a transmission bearer is being requested for speech(ITC=“speech”), for analog data transmission, for example by means ofmodems (ITC=“3.1 kHz Audio”), or is being requested for digital datatransmission (ITC=“UDI”). It is likewise possible to tell whether asynchronous (that is to say bit-oriented) or asynchronous (that is tosay character-oriented) data transmission method is being requested. Theparameter HLCI (High Layer Characteristics Information) in the HLCinformation element denotes a desired application. For example,facsimile is identified by HLCI=“Facsimile GR.3”. HLCI=“Telephony”characterizes a telephone call. The parameter UR (User Rate) is used tosignal requested transmission rates. Information which the PLMN providesrelates to standard settings and to preferred values which are used inthe PLMN. Examples are the indication of available and preferred radiochannel codings, transmission qualities (with or without a data securityprotocol) or maximum transmission rates.

In one particularly preferred embodiment of the method according to theinvention, a digital PLMN, in particular a GSM or a UMTS network, isselected as the mobile communications network.

In a further preferred embodiment of the method according to theinvention, in an HLR of the mobile communications network, a specificnumber of different services are associated with one number such thatidentification of the service is possible, and this is signaled to themobile communications unit with the additional use of the available,collected and collated information elements relating to bearercapabilities which are specific for that service. A complete BC can begenerated and can be sent to the mobile communications unit.

In this case, information which is stored in an HLR is used highlyeffectively. If, for example, a call arrives from an ISDN, then acertain amount of information, such as an ITC, is intrinsicallysignaled, and can be assessed in the HLR. By way of example, a user isallocated one number in the HLR for a number of services. With theassistance of the information which is provided from the landlinenetwork, such as the ISDN, the HLR is in most cases able to uniquelyidentify a call or a corresponding service, and thus to set up acomplete BC for the mobile communications network, that is for example aPLMN BC, and to send this to the mobile communications unit. In a smallnumber of cases, in which the information which comes from the landlinenetwork is not sufficient in order to identify a service, a user or amobile communications unit is allocated two or more numbers, althougheach number is once again responsible for two or more services. Incontrast to the multi-numbering scheme mentioned initially, a user or amobile communications unit is, according to the invention, allocated asmany numbers as necessary in order to make it possible for the landlinenetwork to identify a requested service with the assistance of theinformation supplied to the HLR. This means that the method ensures thatnumbers are allocated as effectively as possible and that an operator ofthe mobile communications network uses fewer numbers than in the case ofthe multi-numbering scheme.

Unique identification is preferably possible in this preferredembodiment of the method according to the invention.

For the situation where unique identification is actually not possible,that is in which, despite information being available from the landlinenetwork for identification purposes, it is not possible to selectpossible services, it is feasible according to the invention (instead ofallocating further numbers to a user) to create the additionalinformation element (as was provided in the first described preferredembodiment of the method), referred to as BACKUP, in the HLR itself, andto fill this with the information which is available in the HLR. Thisis, on the one hand, the information from the landline network (forexample ITC) and the selection (which is already somewhat restricted bythe number allocation process) of possible services. If this BACKUP issent in a signaling message to the mobile communications unit, then theprobability of the mobile communications unit being able to identify thecorrect service may be considerably higher than, for example, in thecase of the single-numbering scheme mentioned initially. The combinationof the two proposed preferred embodiments of the method according to theinvention thus results in a third preferred embodiment of the methodaccording to the invention.

BRIEF DESCRIPTION OF THE INVENTION

Further advantages of the invention will be explained in more detailwith reference to the following exemplary figures, in which:

FIG. 1 shows a procedure for one embodiment of the method according tothe invention.

FIG. 2 shows a number allocation process in an HLR in a mobilecommunications network according to a further preferred embodiment ofthe method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically illustrates which individual steps are carried outin a mobile communications network, such as a PLMN, when a call arrivesfrom a landline network, such as an ISDN. The call which arrives fromthe ISDN and is directed to a mobile communications unit MS, and whichis identified by a specific information element (which is specific forthe ISDN) with regard to the bearer capability, that is an ISDN-BC, anda number MSISDN which has been allocated to the mobile communicationsunit MS, is first of all passed to a so-called Gateway Mobile SwitchingCenter (GMSC). The GMSC now attempts to determine the location of themobile communications unit, that is to say to determine the address(number) of the MSC which is at present controlling that mobilecommunications unit. This MSC is called the Visited Mobile SwitchingCenter (VMSC). In order to determine the location of the mobilecommunications unit, the GMSC first of all sends a routing informationmessage SRI (Send Routing Information) to an HLR (Home LocationRegister) which is responsible for that mobile communications unit MS.This routing information message also includes the ISDN-BC and theMSISDN. The HLR now has the task of determining the location of the userbeing addressed via the MSISDN, including his mobile communicationsunit, and it also has the task of determining whether the user isallowed to use the service being requested by the call. Thisnecessitates a PLMNBC which describes this requested service. ThisPLMNBC can be generated, as described initially, in accordance with thetwo standardized methods, that is to say the single-numbering scheme andthe multi-numbering scheme. As was likewise described in theintroduction, this is generally not possible, or is associated withundesirable boundary conditions. For the description of this preferredembodiment of the method according to the invention, it is thereforeassumed that the HLR is not able to generate a complete PLMN-BC.Accordingly, no PLMN BC is generated in accordance with the GSM/UMTSStandards. The PLMN can therefore not unambiguously determine whichmobile-radio-specific service is being requested. In order to carry outthe task of determining the location of the mobile communications unit,the HLR uses a further message PRN (Provide Roaming Number) to request aso-called roaming number from a VLR (Visitor Location Register) which isresponsible for the MS, with the aid of which roaming number the mobilecommunications unit MS can be located. The MSISDN is now stilladmittedly included in the message PRN, but no BC. The VLR then sends aroaming number for the mobile communications unit MS (MSRN) back to theHLR. The HLR passes on this roaming number MSRN to the Gateway MobileSwitching Center (GMSC), from where the original signaling message IAM(Initial Address Message) received from the landline network is sent toa Visited Mobile Switching Center (VMSC) which is responsible for theMS, with the message IAM including not only the information relating tothe ISDN-BC but also the Mobile Station Roaming Number MSRN. In afurther message, the so-called SIFICSU (Send Information For IncomingCall Set Up), the VMSC now requests the VLR for the PLMN BC which mayhave been generated by the HLR, and which is intended to be included ina signaling message (call set-up message) to the mobile communicationsunit. However, as described above, the VLR cannot supply a completePLMNBC. The VMSC then generates an additional information element, aso-called BACKUP. This BACKUP includes all of the available informationrelating to the bearer capabilities which are specific for that call andfor the service being requested by that call. This BACKUP is then sentin the call set-up message together with other information elements tothe mobile communications unit. By means of this incomplete informationrelating to the bearer capabilities which are specific for that call andfor the service being requested by that call, there is now a greaterprobability of the mobile communications unit MS being able to identifythe correct service than would be the case without any information. Theadditional information element BACKUP is defined as a new optionalparameter for the call set-up message. This makes it possible for oldermobile communications units, which do not know this new functionality,to ignore this parameter and to set up the call as normal. The methodaccording to the invention is thus backwards-compatible, that is it canbe implemented retrospectively in existing mobile communicationsnetworks.

FIG. 2 shows a number allocation process in an HLR in a mobilecommunications network, such as a PLMN. A user of a mobilecommunications unit MS is in the present exemplary embodiment allocatedtwo numbers, specifically MSISDN 1 and MSISDN 2. The user of the mobilecommunications unit MS is authorized to make use of four differentservices. MSISDN 1 can in this case be dialed for three differentservices, for example for a speech service, a FAX service and a dataservice. A fourth service, such as a digital multimedia service, isdialed and requested using MSISDN 2. If MSISDN 1 is now dialed, then theHLR is able with the assistance of the signaling information from theISDN to distinguish between the three services and to select from thesethree services which service is being requested by the call. It can thusuniquely identify the services on the basis of the signaling informationprovided by the ISDN. If a digital multimedia service is beingrequested, then MSISDN 2 must be dialed, since the signaling informationfrom the ISDN is the same as, for example, in the case of a digital dataservice. To this extent, if the MSISDN were the same, the HLR would notbe able to decide whether this was one service or the other. In thiscase, the signaling information from the landline network, that is inthis case the ISDN, is not sufficient to make it possible to ensureunique identification of a service. An additional number MSISDN 2 isthen allocated. In contrast to the multi-numbering scheme, however, anumber is not allocated for each service without taking account of thesignaling information from the landline network, but only when thesignaling information from the landline network is not adequate. Theavailable information relating to the bearer capabilities which arespecific for that call or for the service being requested by that callis used and is assessed effectively.

1. A method for identification of a service requested by a call to amobile communications unit from a fixed network and/or over a fixednetwork and/or over a mobile communications network, comprising:collecting and merging available partial information with respect tobearer capabilities specific for the service in an additionalinformation element in case complete information with respect to thebearer capabilities is not available and a complete information elementincluding the complete information can therefore not be provided;transmitting the additional information element instead of the completeinformation element in a signaling message to the mobile communicationsunit with information elements specific for the service; and utilizingthe additional information element by the mobile communications unit forthe identification of the service.
 2. The method as claimed in claim 1,wherein the additional information element is provided as abackwards-compatible element.
 3. The method as claimed in claim 1,wherein the additional information element is created in a VMSC.
 4. Themethod as claimed in claim 1, wherein the additional information elementis created in an HLR.
 5. The method as claimed in claim 1, wherein theadditional information element obtains the information which itcomprises from the landline network and/or from the mobilecommunications network.
 6. The method as claimed in claim 1, wherein, inan HLR of the mobile communications network, a specific number ofdifferent services are associated with one number to enableidentification of the service, and this is signaled to the mobilecommunications unit with the additional use of the available andcollected information elements relating to bearer capabilities which arespecific for that service.
 7. The method as claimed in claim 6, whereinunique identification is possible.
 8. The method as claimed in claim 1,wherein a GSM or a UMTS network is selected as the mobile communicationsnetwork.
 9. The method as claimed in claim 1, wherein an ISDN is used asthe landline network.
 10. The method as claimed in claim 1, wherein aPSTN is selected as the landline network.
 11. A system foridentification of a service requested by a call to a mobilecommunications unit from a fixed network and/or over a fixed networkand/or over a mobile communications network, comprising: a collectingunit for collecting and merging available partial information withrespect to bearer capabilities specific for the service in an additionalinformation element in case complete information with respect to thebearer capabilities is not available and a complete information elementincluding the complete information can therefore not be provided; atransmission unit for transmitting the additional information elementinstead of the complete information element in a signaling message tothe mobile communications unit with information elements specific forthe service; and a utilizing unit for utilizing the additionalinformation element by the mobile communications unit for theidentification of the service.